The school was placed in limited statutory management in April.
Limited statutory manager Nicola Hornsey released her scoping report and outcomes plan on Monday.
Mrs Quinney said she was "highly satisfied" with the assistance provided by Ms Hornsey.
However, she believed it was important presiding member (chairwoman) Ruth Mitchell acknowledged her part in the lapse of governance practices that led to the request a limited statutory manager be appointed.
"Demonstrating genuine accountability and extending a heartfelt public apology to the students, staff, and wider community would exemplify true leadership and humility in accordance with our Catholic values."
Mrs Mitchell declined to comment.
In her scoping report, Ms Hornsey identified four issues that posed risks to the educational performance, health and safety of pupils and to the operation of the school.
There had been a high turnover of board members as well as turnover of presiding members.
"This has contributed to a lack of alignment between the principal and board regarding the strategic direction of the school."
An intervention plan based on nine Education Review Office’s effective governance statements is being implemented.
Ms Hornsey said the board and principal had moved quickly to improve the way the school was governed.
"Whilst it will take time for the full suite of recommended changes to become embedded, the board is fully committed to their stewardship role and to strengthening the governance foundation of the school.
"A key area of ongoing focus for the intervention is the enhancement of professional working relationships," she said.
